feat: Initial commit

Sources/CliDoc/Node.swift

@@ -0,0 +1,27 @@
+public protocol NodeRepresentable {
+  func render() -> String
+}
+
+public protocol Node: NodeRepresentable {
+  // swiftlint:disable type_name
+  associatedtype _Body: Node
+  typealias Body = _Body
+  // swiftlint:enable type_name
+
+  @NodeBuilder
+  var body: Body { get }
+}
+
+public extension Node {
+  func render() -> String {
+    body.render()
+  }
+}
+
+extension String: NodeRepresentable {
+  public func render() -> String { self }
+}
+
+extension String: Node {
+  public var body: some Node { self }
+}